1. Field of the Invention
The present invention relates to a method and apparatus for controlling an amount of fuel to be injected into a diesel engine, and more particularly to a method and apparatus that can reduce shock upon clutch engagement while an engine brake is applying.
2. Description of the Related Art
Conventionally, a basic amount of fuel injection in a diesel engine is determined based on an engine revolution speed and an accelerator opening, and this basic value is modified based on temperature of water flowing in the engine and/or intake air temperature in order to determine an ultimate (or target) amount of fuel injection.
Incidentally, when a driver is operating a vehicle equipped with a manual transmission, he/she may perform a shift-down operation to the transmission (gear shift-down) while an engine brake is being applying. In this situation, the engine revolution speed often rises steeply upon engagement of a clutch. This results in great change in engine revolution speed. This is primarily caused by negative acceleration due to the engine brake and inertia of the vehicle. As the clutch is engaged, the load on the vehicle is first shifted forward and then shifted backward because of reaction. In other words, back-and-forth oscillation occurs. This results in very fast change in the engine revolution speed, as mentioned earlier. As the engine revolution speed varies rapidly, passengers in the vehicle are forced to move back and forth and experience great uncomfortableness.